The atomization technology is widely used in mass-transfer heat-transfer processes such as concentrating, drying, absorption, flue gas and air purification. Traditional atomization technology uses gas as a continuous phase and liquid as a discontinuous phase, and generates high-speed flow atomization by forcing pressurized fluid into spray nozzle pores, but such technology has many drawbacks such as larger loss of kinetic energy, poor atomization effect, easy clogging of the pores that are caused by frictional resistance generated when liquid passes through the pores. An improved atomization technology atomizes the pressurized fluid by centrifugation or pre-positioned spiral structure, but, although the problem of pore clogging is alleviated due to the large liquid flowing passage, there are still problems of scaling or clogging of the spiral nozzle, which negatively affects the atomization effect. These traditional or improved atomizing spray nozzles adopt the configuration with a stationary spray head where the fluid passes through a special structure to attain fast motion or dispersion by colliding, wherein most energy is absorbed by the structural component that is head-on collided with, so the distribution range and distribution effect of fluid in space as well as the duration and opportunity of gas-liquid contact are limited, which significantly influences the mass-transfer heat-transfer and reaction effect.
A centrifugation atomizing spray head consists of an atomizing plate, a swirling plate and a flow separating plate. Under certain pressure, the fluid passes through pores in the flow separating plate and converges into an annular groove, and then enters a swirling chamber of a swirling center along the tangential direction of the swirling plate, so as to generate high-speed rotating motion and be ejected from a central hole. By the action of centrifugal force, the fluid overcomes its own viscous force and surface tension, so as to be shattered into fine droplets and form a conic atomization area with a certain angle. However, this centrifugation atomizing spray head still has disadvantages such as uneven droplet distribution, small intermediate water amount, sprayed water with big water drops or water column, small covered area, poor atomization effect. Therefore, it is very worthwhile to develop a new high-efficient atomizing spray head which converts the kinetic energy of pressurized fluid into the effective energy of sufficient atomization by “guidance according to trend”.
By means of cyclone de-dusting and swirling liquid separation, an effective dust and fog elimination process may be achieved. Similarly, by completely relying on the initial kinetic energy of the fluid entering the tower, swirling motion is generated when the fluid enters a cylindrical body along its tangential direction from an inlet pipe and changes moving direction upon being blocked. Although the generated centrifugal force brings dust and/or droplets with larger density towards the surrounding wall so as to achieve preliminary gas-liquid separation or gas-solid separation, the cyclone de-dusting structure similarly causes that the kinetic energy of the fluid is quickly absorbed by the equipment and thus only local swirling with limited effect is formed. As a result, the dust and fog elimination effect of the cyclone equipment is limited, and its processing effect still needs to be improved. Although the flow velocity of the fluid can be increased by adding more blowing and discharging equipment, the energy loss would be significantly increased, and the increase of gas flow velocity would negatively affect the desulfurization effect. Currently, dust such as PM10 and PM2.5 in flue gas must be treated with bag filter de-dusting or electrostatic de-dusting to be mostly eliminated so as to meet the discharge standard.
De-dusting and desulfurization by water spray is a most common means for purifying the flue gas. Wherein, by spraying dilute alkali water, the contaminants such as dust particles, sulfur dioxide and nitrogen oxide get into sufficient contact with water droplets or a water film in the air or on the filler surface so as to be captured, with a de-dusting efficiency of 80%-90% and the ability to eliminate harmful gas such as sulfur dioxide and nitrogen oxide. However, because of large gas amount, small water amount, poor dispersion of water droplets, short contact time and unsatisfactory phase contact effect, the above-mentioned problems of poor purification and contaminant elimination effect, high energy lost and processing cost still exist. As the sprayed water droplets do not form liquid swirling and cannot drive gas swirling, under the dual action of gravity and initial kinetic energy, the liquid that has been sprayed downwards quickly falls onto the tower bottom or forms wall flow, and as a result, there is serious wall flow and wall sticking phenomenon and the mass-transfer heat-transfer effect still needs to be improved. Currently, in order to ensure the desulfurization effect, measures such as increasing the tower diameter, increasing the tower height, reducing gas velocity, adding multiple layers of spray heads are taken, which then leads to large investment, large space occupied by the equipment, high energy loss, poor processing effect, and especially that the coal-burning boiler tail gas after purification can hardly meet the sulfur dioxide and dust discharge standard of burning boilers. The largely discharged dust and acidic gas have already causes frequent, continuous and large-scale haze weather that severely influences people's normal life. Even if the tail gas meets the national discharge standard, it still actually is a major source that causes acid rain and haze. The measures currently taken, such as controlling coal using amount, removing coal-burning boilers from the downtown area, restricting use of cheap coal burned by boilers, using scarce natural gas as substitute fuel, cannot fundamentally solve the problem, but only add to the shortage of fuel gas and add to living cost of enterprises and civilians. Therefore, it has significant meaning to develop atomizing technology that has notable effect of high-efficiency and energy-saving.
Artificial raining is, choosing a proper timing according to physical characteristics of various cloud layers and spreading catalysts such as dry ice, silver iodide and salt powder in to the cloud with airplanes or rockets, so as to cause the cloud layer to rain or increase its raining amount, thereby relieving or alleviating farmland drought, increasing the irrigation water amount or water supply ability of water reservoirs, or increasing power generating water amount thereof.
Currently, artificial raining mainly uses methods such as cold cloud seeding, warm cloud seeding and dynamic seeding, and the applied catalysts are mainly dry ice, silver iodide and salt powder, which have problems such as large energy loss, harsh requirements of the climate cloud layer, and high cost.
Fire disaster is one of the most frequent and most common major disasters that threat the public safety. While utilization and control of fire is a symbol of human civilization progress, two important tasks of fire-fighting work are preventing fire disaster and reducing the damage of fire disaster, and therefore it is very worthwhile to develop the technology for effective fire disaster prevention as well as high-efficient and fast fire extinguishing. Combustion is an intensive exothermic chemical oxidation reaction that requires air participation, and thus fire extinguishing is a process of quickly stopping combustion by means of isolating and diluting air, covering the burning area, reducing the temperature, or combination thereof. When extinguishing initial small fire or extinguishing fire of small amount of oil, the fire is often covered by fine river sand; flame or small fire at a container mouth can be extinguished by directly covering the fire with an asbestos quilt or a wet cotton quilt; the foam fire-extinguisher used at home can extinguish initial small fire, it uses aluminum sulfate and sodium bicarbonate as fire-extinguishing fluid which, when mixed by inverting the extinguisher during usage, react to produce a gas-liquid-solid mixture of aluminum, water and carbon dioxide that can be directly sprayed to cover the flame and inflamer so as to achieve the purpose of reducing the temperature and isolating the air; fires in places such as precision instrument, electrical equipment, oil tank area, storage, oil pump room, oil operation room are often extinguished by carbon dioxide fire-extinguishers or carbon dioxide powder fire-extinguishers. However, if a small fire cannot be quickly extinguished, it usually evolve into a big and fierce fire and at that point the aforementioned means cannot take effect, then large fire-fighting equipment such as a fire-fighting lance and a fire-fighting truck must be used to extinguish the big fire. Thus, if initial fire cannot be extinguished quickly and effectively, the best opportunity to fight the fire will be missed and a major disaster might be caused.
As described above, the fire extinguishing methods in prior art actually use measures such as reducing the temperature or oxygen concentration or contact thereof so as to achieve the purpose of terminating the oxidation reaction and extinguishing the flame. However, the fire extinguishing methods in prior art have the problems of uneven dispersion of the fire-extinguishing solid and liquid, large use amount of the fire-extinguishing agent, poor fire-extinguishing effect, severe damage of property, high cost of use, small fire-extinguishing area, and inability to effectively eliminate toxic smoke.
When the fire-extinguishing process is analyzed according to principle of chemical engineering, the currently used various fire-fighting equipment and apparatuses do not perform atomization and dispersing of the fire-extinguishing agent very well, and their fire-extinguishing processes have poor mass-transfer heat-transfer performance. Although the water-type fire-fighting apparatus have large water pressure and water amount, its atomization effect is poor, its spray area is small, its water use amount is large, and because the water can hardly vaporize effectively to absorb heat and dilute air at the moment when coming into contact with the flame, large amount of water get lost instantly, which leads to a situation that “a truckload of water cannot extinguish a fire”. If the fire cannot be extinguished in time, serious damage of property will be caused, and the large amount of toxic gas and PM2.5 produced by burning usually result in significant casualty and social panic.
In order to enhance the fire-extinguishing effect, some improvement of water flow dispersion is made to the spray head in prior art. Water sprinkler with a simple structure that is often used indoor only disperse the water flow into water drops by means of a water splashing deflector, wherein no fine water fog is produced, and although the water spray area is notably increased as compared to direct water ejection, its covering area is not enough, its distribution is uneven, its intermediate water amount is small, the water has extremely big drops or is in a state of water column, and thus the fire-extinguishing effect is unsatisfactory. The fire-fighting lance that is often used for fire-extinguishing has reduced outlet diameter and increased outflow velocity, so that water is splashed onto an object to generate atomization, with most of the kinetic energy being absorbed by the object that water is splashed onto, and as affected by the field environment, the distance and the inflamer shape, its effect is limited, it has small covering area and poor atomization effect, and it cannot suppress the flame in a short time, which leads to very poor water utilization rate and rather poor fire-extinguishing efficiency. Some high-pressure fine-water-fog spray heads may have better atomization effect, but requires a pressure of about 10 MPa, which might easily causes personal injury or property damage, have very high cost, and thus can hardly be popularized. In order to assist the atomization, a specific mechanical structure such as a rotary core, a barrier block or a spiral spring is added into the spray head in prior art, wherein the rotary core type of spray head is the most common atomizing spray head, and its working principle is that the fluid driven by pressure enters a swirling chamber and generates intense rotating motion so as to be ejected from a spray head, thereby achieving atomization by the action of centrifugal force, however, when used for fire-extinguishing, it has the following problems:
(1) Such a rotary core structure or ejection atomizing apparatus has a “mechanical obstruction” function towards the fluid, which causes that most kinetic energy of the fluid is absorbed by the spray head body, and therefore, the fluid sprayed by the spray nozzle has a low sprayed, covers a short distance, can hardly get close to the flame, thus being unable to effectively overcome the airflow resistance of the flame, unable to reach the flame interior and burning surface to perform fire-extinguishing, and unable to sufficiently exert the function of covering the burning surface and reducing temperature thereof. The spray protection radius of each spray nozzle is normally about 0.5 m, and multiple spray nozzles, which add to the cost, can hardly enhance the effect.
(2) Atomization assisted by centrifugal force forms a hollow cone, which causes uneven distribution of the spray density, and thus the function of high-efficient fire smothering by fine water fog cannot be sufficiently exerted. Using a barrier block or a spiral spring would similarly causes that most kinetic energy is absorbed and that the water drops produced by the atomizing spray head have large diameters. Therefore, it has significant meaning to develop a new device that can instantly extinguish big fire in a water-saving high-efficient way.
To sum up, sufficient liquid atomization has broad application demands, but has certain technical bottleneck that is challenging. The various stationary atomizing spray heads in prior art have large loss of kinetic energy and unsatisfactory atomization effect. Although there are spray heads that perform watering in a rotating manner, those spray heads have poor atomization effect due to their low rotating speed or un-optimized spray nozzle design, and thus are not applied in other fields. Although performing high-speed rotation with a motor can improve the dispersion effect, but this arrangement still has many problems such as high cost, complicated structure, large energy loss, limited usable range, thus being difficult to popularize. Therefore, it has important meaning to develop an atomizing device that can be widely applied in industrial and agricultural fields such as fluid atomization, flue gas and air purification, spray drying or concentrating, smoke abatement and fire extinguishing.